Bumper for picker stick control



Feb. 11, 1969 c. R. MESSER 3,426,808

BUMPER FOR PICKER STICK CONTROL Filed May 29, 1967 INVENTOR. CHESTER R. MESSER BY Z W J Z? United States Patent F 2 Claims ABSTRACT OF THE DISCLOSURE A picker stick bumper of woven fabric including a bowed bridge portion enclosing an inner reenforcing portion, either or both of which being stiffened in separate areas by impregnation of polyurethane or the like.

This invention comprises a new and improved picker stick bumper serving definitely to limit the path of the picker stick in its shuttle activating oscillation and absorb the momentum of the stick in bringing it to rest at the end of its stroke.

The duty performed by this type of bumper is very severe leading to short life in practice and serious down time for replacement. Accordingly every expedient to prolong the life of the bumper is of outstanding importance to the manufacturer using the loom.

In one aspect my improved bumper is characterized by a nylon strap shaped to present a bowed convex enclosing bridge portion stiffened by impregnation of polyurethane at its ends and in a central area and a convoluted or bowed strap portion tending yieldingly to resist deformation of the bridge portion of the bumper and having stiffened areas separated by more flexible areas.

The occurrence in the structure of areas stiffened by impregnation of a synthetic resin such as polyurethane in spaced relation to unimpregnated areas of greater flexibility has been found to give the resulting bumper an unexpectedly quick acting damping effect as a result of compression of slight amplitude. This characteristic apparently results in imparting longer life to such a bumper than has been found in bumpers heretofore available to the industry.

These and other features of the invention will be best understood and appreciated from the following description of two preferred embodiments thereof selected for purposes of illustration and shown in the accompanying drawing in which:

FIG. 1 is a view in elevation of one type of bumper and the end of a picker stick,

FIG. 2 is a fragmentary plan view of the fabric strap component thereof, and

FIG. 3 is a plan view of a bumper of another type in which the invention is embodied.

The bumper shown in FIG. 1 is formed from a single strap of woven nylon mounted upon a fixed rod shown as projecting horizontally from a portion of the loom and carrying a sliding head 11 through which passes the picker stick 12.

The nylon strap has a portion convoluted to present six U-shaped loops 13 disposed in oppositely and alternatively opening direction and connected by common straight legs. The sides of the loops and both ends 14 and 15 of the strap are perforated to slide upon the rod 10 as indicated in FIG. 2 where perforations 24 are shown as spaced between areas stiffened by impregnation of polyurethane.

The inner looped portion of the bumper merges at one end into a bowed convex bridge portion 16 which encloses the looped portion of the bumper and is secured at the other end to the outer arm of the endmost 100p.

3,426,808 Patented Feb. 11, 1969 The superposed ends of the two strap portions are overlapped and secured together. They are stiffened by impregnation in the lined areas designated by the reference character 13 in FIGS. 1 and 2 and these are separated by unimpregnated and more flexible spaces. The impregnated areas have tapered ends consequently tending to distribute working strain in the loops rather than concentrating it in a line across the strap. More specifically the U-shaped bends of the loops are impregnated and stiffened while the intermediate connecting legs of the bends remain unstiffened, flexible and not more than slightly impregnated if at all. It has been found that this alternating arrangement of stiffened and unstiffened areas contributes largely to improving the checking effect and increasing life of the bumper.

The bumper is designed to receive and cushion the oscillating movement of the head 11 and to limit movement of the picker stick 12 in the direction of the arrow. When end-wise pressure is applied to the bumper of FIG. 1 by the head 11 the loops 13 momentarily tend to close and the bridge portion 16 is shortened against the yielding resistance of the enclosed loops and its own inherent resiliency.

The bumper of FIG. 3 is organized about a cast iron yoke having a shank 30 and divergent rounded arms 31. A strap of woven nylon is wrapped at its end about the arms 31 and secured to their outer surfaces by bolts 32. It extends as a curved convex bridge 35 from one arm to the other, corresponding in this respect to the bridge 16 of FIG. 1. This strap 35 is impregnated and stiffened in a wide intermediate area and in both end areas where it is perforated for the bolts 32. The strap is unimpregnated and flexible in the unlined areas 34 where it is wrapped about the arms 31.

In this bumper the reinforcing strap 36 is a separate piece of woven nylon and is secured in loop formation to the inner surfaces of the arms 31 by the same bolts 32 that secure the bridge member. The strap 36 is stiffened by impregnation with polyurethane in its end areas and in an intermediate area of its loop where it contacts with the inner surface of the bridge 35 and so resists distortion thereof under impact of the picker stick.

It will be apparent that both the bumpers herein shown are similar in that they present a bowed convex bridge of woven synthetic fabric which is flexed in damping the momentum of the picker stick and reinforced or supported against such flexing by a supplementary enclosed loop or loops of the same material similarly impregnated in spaced areas.

I have discovered a novel process of treating woven straps of synthetic resinous fabric that results in an unexpected improvement in the service and life of the strap in a bumper. It consists in impregnating and stiffening a length of woven synthetic fabric with a resinous solution such as polyurethane in spaced areas separated by an unimpregnated intermediate area, causing the intermediate area to become stiffened to a lesser and progressively varying degree by migration of polyurethane or the like from the said spaced impregnated areas and then molding the strap to impart bow or loop formation to the intermediate areas.

The results are that the fully impregnated and stiffened areas of the strap acquire an increased resiliency and wear resistance while bowed portions of the strap may be so molded that they will hinge under the impact of the picker stick. Moreover, since the stiffening effect of the migrating polyurethane is progressively varying in its effect the hinge action is spread in the bowed area as distinguished from being concentrated at a sharp line across the strap. Concentration of stress is thus avoided 3 and objectionable vibration of the stiffened areas is dampened or eliminated.

Having thus disclosed my invention and described an illustrative embodiment thereof, I claim as new and desire to secure by Letters Patent:

1. In a picker stick bumper employing a stationary supporting element and a conformed nylon strap, wherein the improvement consists in that the nylon strap is shaped to present a bowed outwardly convex bridge portion, stiffened by impregnation of urethane at its ends and in an intermediate area, and a curved strap portion comprising alternatively arranged U-bends having common connecting legs, the areas of the bends being stiffened by polyurethane impregnation and the intermediate areas of the legs being relatively flexible and unstiffened.

2. A picker stick bumper as defined in claim 1, further characterized in that areas adjacent to those stiffened by impregnation of polyurethane are stiffened to a lesser and progressively varying degree by migration of polyurethane from the impregnated areas.

References Cited UNITED STATES PATENTS 2,760,526 8/1956 Hussey 139-166 3,228,429 1/1966 Messer 139-161 FOREIGN PATENTS 1,254,181 1/1961 France.

130,798 8/1919 Great Britain.

799,916 8/1958 Great Britain.

448,600 5/1949 Italy.

316,693 12/ 1956 Switzerland.

JAMES KEE CHI, Primary Examiner. 

